Railway braking apparatus



Aug. 2, 1932. H. c. cLAusEN .ET AL RAILWAY BRAKING APPARATUS Filed July 22, 1931 Sm. NN MUN .NN JWKNFQWWBNQQ QR NNQ NN MUN LBQMV w Sim .w w w .N Q wN mN m MN Mw um em sw m m N wmv INVENToRs H, C C /a usenfi'w yao `- movable toward and away f disclosed and Patented Aug. 2, 1932 p srarss PATENT oFFrcE HABOLD C. CLAUSEN, OF SWISSVALE, AND JOHN W. LOGAN, JR., OF EDGEWOOD, ENN- SSIGNOB-S T THE UNION SWITCI-I & SIGNAL COMPANY, OF SWIS'SVALE, V

PNNSYLVANIA, .A COBFOBATION OF PENNSYLVANIA BAILWAY BRAKING API'ARATUS i Applcationfiled July 22, 1931. Serial No. 552,384.

Our invention relates to railway braking apparatus, and particularly to braking apparatus of the type comprisingwheel engaging braking bars .located beside a track rail, and from the rail into braking and non-braking positions. More particularly, our invention relates to apparatus of the type 'described in which the bralring bars are arranged to be moved to thelr braking positions by a fluid pressure operated motor, and to be restored to their non-braking positions by suitable biasing means, such as gravity. Specifically, the present invention is an improvement on apparatus of the type claimed in an application foi` Letters Patent of the United States filed by Herbert L. Bone on February 19, 1931, Serial No. 516,883, for railway braking apparatus.

One object of our invention is the provision in apparatus of the type described of means for normally limitng the movement of the braking bars away from the rails to an amount which is just sufiicient to clear freight car wheels ofordinary width, but for at times permitting sufiicient additional movement of the braking bars away from the rails to clear the wide driving wheels of locomotives, thus afi'ecting a considerable reduction in the amount of the fluid pressure Which must be supplied to the motor over that which would have to be supplied to the motor if the braking bars were normally moved away from the rails far enough to clear the wide driving wheels of locomotives.

l/Ve will describe one form of apparatus embodying our invention, and will then point out the novel features thereof in claims.

In the aocompanying drawing, Fig. 1 is a view, partly diagrammatic and partly crosssectioned, illustrating one form of apparatus embodying our invention. Fig. 2 is a sectional view on line II-II of Fig. 1.

Similar reference characters refer to similar parts in both views.`

Referring to the drawing, the reference character 1 designates one Vtrack rail of a stretch of railway track, which track rail, as here shown, is secured to a rail support 2 mounted on an adjacent pair of the usual crossties 3, only one crosstie being visible in the drawing. Associated with the rail 1 is a car retarder comprising two braking bars A1 and A2 located on opposite sides of rail 1. Each of these braking bars comprises, as usual, a brake beam 4 and a brake shoe 5.

The braking bars A1 and A2V are arranged to be moved` toward and away from the rail 1 through the medium of a lever V6 which is pivotally mounted at one end on a pivot pin 8 carried by the rail support 2, and a lever 7 which is pivotally Vmounted intermediate its ends on the pivot pin 8. `The lever 6 is inclined upwardly and extends away from the rail 1, and is provided in ts upper surface with a groove 6a which receives the braking bar A1. The one end 7a of the lever 7 .is likewise inclined upwardly and extends away from the rail at the opposite side of the rail from the lever 6, and the other end of 7b and the lever 7 is inclined downwardly and extends from the rail l'below the lever 6. The end 7 a of the lever 7 is provided in its upper surface with a groove 70, similar to the groove 6a in the lever 6, which groove receives the braking bar A2. The parts are so arranged and so proportioned that if the Outer or free ends of the levers 6 and 7 are moved apart,

the braking bars will be moved towardthe rails into their effective or braking positions. VVhen the braking bars occupy their braking positions, the brake shoes 5 will engage .the opposite side faces of a car wheel traversing rail 1, and will retard the speed of the car. The center of gravity of the lever 6 and braking bar A1 is considerably to the left of the pivot pin 8 so that this lever will normally tend to rotate .in a counter-clockwise direction about the pivot pin. Similarly, the center of gravity of the lever 7 and braking bar A2 is to the right of pivot pin 8 so that this lever .will normally tend to rotate in a clockwise direction aboutthe pivot pin. It will be appa-rent, therefore, that when no force is applied to the free ends of the levers 6 and 7 to move them apart, the free ends of these levers will move toward each other, thereby moving the braking bars to their ineffective or non-braking positions in which they are illustrated in the drawing.

For moving the levers apart we provide apparatus embodying our invention which apparatus we will now describe. rlThis apparatus in the form here shown, comprises a fluid pressure motor h/I, the cylinder 9 of which is pivotally attached to the free end of the lever 6 by means of trunnions 9b formed on the side of the cylinder and extending through suitable openings in bifurcation 6b formed on the lever 6, as best seen in Fig. 2. Located in the cylinder is a main piston 10 and an auxiliary piston 11. The main piston 10 is attacned to a piston rod 13 the free end of which is connected, by means of an adjustable eyebolt 14 and pivot pin 15, with the free end 7b of the lever 7. It will be apparent, therefore, that simultaneous movement of the piston 10 downwardly and the cylinder 9 upwardly will move the braking bars toward their braking positions. The auxiliary piston V11 is attached to a hollow piston rod 16, and as shown in Fig. 1 is movable between a projected position, in which it is illustrated in the drawing, and a retracted position in which it engages a reinovable distance piece 12. The hollow piston rod 16 establishes communication between a chamber 91, formed at the upper end of the cylinder 9, and the region of the cylinder between the pistons 10 and 11, as will be readily understood from an inspection of the drawing. It follows that when fluid pressure is admitted to the chamber 9a, fluid pressure will be supplied to the region of cylinder 9 between the pistons 10 and 11.

It will be plain from an inspection of the drawing that when the auxiliary piston 11 occupies its projected position, it limits the stroke of the main piston 10 and, hence, pre- Vents the brakng bars from moving as far away from the rail 1 as when the auxiliary piston occupies its retracted position. The parts are so proporticned that wiien the main piston 10 engages the auxiliary piston 11 in the projected position of the latter, the distance away from the rail 1 that the braking bars A1 and A2 are moved will be just sufficient to clear car wheels of Ordinary width, but that, when the main piston 10 engages the auxiliary piston 11 in its retracted position, the distance away from the rails that the braking bars A1 and A2 are then moved will be sufficient to clear the usual wide driving wheels of locomotives. The function of the distance piece 12 will be explained more fully hereinafter.

The motor M is controlled by four magnet valves designated by the reference characters V1 to V4,'respectively, and each comprising a Valve stem 17 biased to an upper position by means of a spring 18, and provided with a winding 19 and an armature 20. VVhen Valve V1 is energized, Valve stem 17 of this Valve moves downwardly against the bias eX- isca/ice erted by spring 18, and a pipe 21 which conimunicates with the region of cylinder 9 between the auxiliary piston 11 and the distance piece 12 through a pipe 22 and a port 23 in the distance piece 12, is then connected with a pipe 24 which is constantly supplied with fluid pressure, usually air, from a suitable source not shown in the drawing. 'When Valve V1 is deenergized, however, Valve stem 17 of this Valve is moved upwardly by spring 18, and pipe 21 is then disconnected from pipe 24 and is connected with a pipe 25. When Valve V2 is energized, valve stem 17 of this Valve moves downwardly, thereby connecting pipe with a pipe 26, but when Valve V2 is deenergized as shown in the drawing, pipe 25 is disconnected from pipe 26. W hen Valve V3 is energized, pipe 26 is vented to atmosphere through a port 57, but when Valve V3 is deenergized, pipe 26 is discennected from port 57. VVhen Valve V4 is energized, valve stem 17 of this Valve moves downwardly and connects a pipe 27, which communicates with the chamber 9a, with the pipes 21 and 22. VVhen Valve V4 is deenergized, however, pipe 27 is disconnected from the pipes 21 and 22, and is connected with pipe 26.

The valves V are controlled in part by a plurality of pressure responsive devices PW, P and PW, each comprising a Bourdon tube 28 connected to the pipe 27, and hence subjected to the pressure in the region of cylinder 9 between the pistons 10 and 11. Each Bourdon tube 28 controls two contacts 29- 29a and 29-29. rThe pressure responsive devices Plo, P40 and P are so constructed that they will operate successively as the pressure in the region of cylinder 9 between the pistons 10 and 11 increases. For example, for all pressures below 10 pounds per square inch, contact 29---29a of each of these devices is closed. ff the pressure exceeds 10 pounds per square inch, however, contact 29---29ZL of device P10 opens, and if the pressure exceeds 20 pounds per square inch, contact 29-29b of device PIO closes. In similar manner, the pressure responsive devices 1340 and P are adjusted to open their contacts 29--29a at 40 and 70 pounds per square inch respectively, and to close their contacts 29-29b at 50 and 80 pounds per square inch, respectively. f course, these 'specific pressures are not essential but are only mentioned for purposes of explanation.

The valves V are also controlled by means of a manually operable lever L which, as here shown, is capable of assuming six positions, indicated by dotted lines in the drawing, and designated by the reference characters pl to 796, inclusive. The lever controls a plurality of contacts 303-6, 311, 321, 332, 34, 353, 364 and 375. Contact 303-6 is closed 'in the 293 position of the lever,l the 206 position or any position intermediate these two positions tact 361 is closed in the 204 position of the lever; and contact 375 is closed in the p posi-` tion of the lever.

Lev-er L will usually be located at a'point remote from the braking apparatus, as in the control cabin of a classification yard car retarder system and will be connected with the apparatus by means of line wires eXtending from the control cabin to the braking apparatus.

As shown in the drawing, lever L occupies its 102 position, which is the position Which it normally occupies when no cars are to be retarded, and all the contacts of lever L, with the exception of contact 332 are therefore open. The Valves V1, V2 and V2 are therefore all deenergized, but Valve V3 is energized over a circuit which passes from battery B through line Wire 38, Winding 19 of Valve V3, line Wire 39, Wire 40, contact 332 of lever L, and common Wire 41 back to battery B. Since Valve V1 is deenergized, pipe 24 is disconnected from pipe 21, and the supply of fluid pressure to all regions of cylinder 9 is therefore cut off, as will be apparent from an inspection of the drawing. Furthermore, since valVes V2 and V4 are deenergized, fluid is trapped in the region of cylinder 9 between the auxiliary piston 11 and the distance piece 12, so that the auxiliary piston 11 is held in its projected position. In addition, since Valve V3 is energized and Valve V*1 is deenerffized, the region of cylinder 9 between the pistons and 11 is vented to atmosphere through hollow piston rod 16.y Chamber 9a, pipe 27, Valve V1, pipe 26, Valve V3 and port 57, and the braking bars are therefore held by gravity in the positions in which the main piston 10 engages the auxiliary piston 11 in the projected position of the latter. The braking bars Will therefore just clear freight car wheels of Ordinary Width. Due to the fact that the region of cylinder 9 between the pistons 10 and 11 is vented to atmosphere, all of the contacts 29---29a of the pressure responsive devices P are closed, and

all of the contacts 29---29b are open.

In explaining the operation of the apparatus, We Will first assume that the operator wishes to make a comparatively light brake application. To do this he moves lever L to its ps position, thereby opening contact- 332 and closing contacts 332-6 and 352. The opening of contact 332 interrupts the circuit previously traced for Valve V3, and valVe V3 therefore becomes deenergized, thus discounecting pipe 26 from port 57 and hence disconnecting the region of cylinder 9 between the pistons 10 and 11 from atmosphere. The closing of contact ,332-G completes a circuit for Valve V1, and current floWs from battery B through line Wire 39', winding 19 of Valve V1, line Wire 42, contact 302-6 of lever L, and common'Wire 41 back to battery B. Valve V1 therefore becomes energized, and connects pipe 24 With pipe 21, so that fluid at full line pressure is now supplied to cylinder 9 between auxiliary piston 11 and distance piece 12 to hold auxiliary iiston 11 in its projected position. The closing` of contact 352 completes a circuit for Valve V1 passing from battery B through line Wire 38, winding 19 of valve V1, line Wire 43, wire 44, contact 29-291 of pressure responsive device P111, Wire 45, contact 353 of lever L, and common Wire 41 back to battery B. Valve V4 therefore also becomes energized, thus disconnecting pipe 27 from pipe 26, and connecting this pipe with pipes 21 and 22. As a result, fluid pressure is now also supplied to the region of cylinder 9 between the pistons 10 and 11, and piston 10.

and cylinder 9 therefore move relative to each other in such manner that the braking bars are moved to their braking positions. As soon as the fluid in cylinder 9 between the pistons 10 and 11 reaches 10 pounds per square inch, contact 29-292 of pressure responsive device 1210 opens and interrupts the circuit just traced for Valve V4. Valve'V'* therefore becomes deenergized and cuts off the supply of fluid to the region of cylinder 9 between the pistons 10 and 11 until the pressure in this region of the cylinder again decreases below 10 pounds per squareinch, at Which time Valve V2 will again become energized and will again adniit fluid to this region of the cylinder. If the fiuid in cylinder 9 between the pistons 10 and 11 increases to a pressure of pounds per square inch for any reason, contact 29-29b of pressure responsive device 1210 Will become closed and Will complete a circuit .for Valve V 3 which passes from battery B through line Wire 33, Winding 19 of Valve V 2, line Wire 39, Wire 46, contact 29-2911 of pressure responsive device P1, Wire 45, contact 352 of lever L, and common Wire 41 back to battery B. ValVe V3 will therefore become'energized, and since contact 29 29a of pressure responsive device will then beV open so that Valve V1 Will be deenergized, the pressure in the region of cylinder 9 between the pistons 10 and 11 will be Vented to atmosphere until the pressure again decreases below 20 pounds per square inch and permits contact 29-29b of pressure responsive device 1210 to open. It Will be seen, therefore, that when lever L occupies its 293 position, the braking bars Will be held in their braking position by a Vpressure of between 10 and 20 pounds per square inch.

If the operator desircs to inake a more powerful brake application, he Will move lever L to its 294 position in Which contacts 303-6 and 36A1 are closed. The operation of the apparatus, under these conditions, is siniilar to that just described With the following exceptions. Valve V4 will now become energized over a circuit which passes from battery B through line Wire 38, winding 19 of Valve V4, line Wire 43, wires 44 and 47, contact 29-29f* of pressure responsive device P4, Wire 48, contact364 of lever L, and common Wire 41 back to battery B.V `When the fluid in the regions of cylinder 9 between the pistons 10 and 11 has reached a. pressure of 40 pounds per square inch, contact 29 29a of pressure responsive device P will open and will interrupt the circuit just traced for valve V* so that valve V4 Will become deenergized and Will cut off the supply of fluid pressure to the region of cylinder 9 between the pistons 10 and 11; and if the pressure in cylinder 9 between the pistons 10 and 11 exceeds 50 pounds per square inch, contact 29 29b of pressure responsive device P*O Will close, and will complete another circuit for Valve V3 Which passes from battery B through line Wire 38, winding 19 of valve V3 line Wire 39, wires 46 and 49, contact 29-29b of pressure responsive device P1, Wire 48, contact 36* of lever L, and common Wire 41 back to battery B. TWhen this latter circuit is closed, Valve V3 will again become energized and Will vent the region of cylinder 9 between the pistons 10 and 11 to atmosphere until the pressure between these pistons decreases below 50 pounds per square inch. It Will be apparent, therefore, that when lever L occupies its 294 position, the braking bars will be held in their bralring positions by a pressure of between 40 and 50 pounds per square inch.

If lever L is moved to its 10,5 position, valve V1 Will become energized over the circuit previously described including contact 303-G of lever L, and valve V4 will become energized over a circuit which passes from battery B, through line Wire 38, winding` 19 of valve V4, line Wire 43, Wires 44, 47 and 50, contact 29-29b of pressure responsive device PW, Wire 51, contact 375 of lever L, and common Wire 41 back to battery B. Fluid pressure Will therefore be supplied to the region of cylinder 9 between the auxiliary piston 11 and the distance piece 12 and between the pistons 10 and 11. lVhen the pressure of the fluid in the region of the cylinder 9 between the pistons 10 and 11 reaches 70 pounds per square inch, contact 29-29EL of pressure responsive device P70 Will open and Will deenergize valve Vi, and if the pressure reaches 80 pounds per square inch, contact 29-29b of pressure responsive device 1370 Will close, and Will complete another circuit for valve V3, this latter circuit passing` from battery B through line Wire 38, Winding` 19 of Valve V3, line Wire 39, Wires 46, 49 and 52, contact 29--29b of pressure responsive device PW, Wire 51, contact 375 of lever L, and common Wire 41` back to battery B. Valve V3 Will therefore become energized and Will vent fluid from the region of cylinder 9 between the pistons 10 and 11 to atmosphere until the pressure again decreases below 80 pounds per square inch. It Will be seen, therefore, that in the 295 position of the lever, the braking bars are held in their braking positions by a pressure of between 70 and 80 pounds per square inch.

If it is desirable to apply still higher braking forces, the operator Will move lever L to its 296 position. Valve V1 Will then become energized over the circuit previously described including contact 303-G of lever L, and valve V4 also becomes energized and Will subsequently remain energized by virtue of aI circuit Which passes from battery B, through line Wire 38, Winding` 19 of Valve V4, Wires 43 and 53, contact 346 of lever L, and common Wire 41 back to battery B. It Will be apparent, therefore, that under these conditions, the braking bars Will be held in their braking positions by fluid at full line pressure.

lzVhen lever L occupies any one of its 113, pt, 295 or pa positions, that the bralring bars ccupy their braking positions and the operator Wishes to restore the braking bars to their non-braking positions in which they are illustrated in the drawing, he will restore lever L to 722 position. When he does this` all circuits previouslytracedforvalveV4 will be interrupted, and the circuit previously described for valve V3 including` contact 332 vill become closed. Valve V* will therefore become deenergized and valve V3 will become energized. As a result, the supply of fluid pressure to all regions of cylinder 9 Will be cut off, and the fluid pressure which was previously supplied to cylinder 9 between the auxiliary piston 11 and the distance piece 12 will be trapped in this region of the cylinder to hold the auxiliary piston in its projected position .in which it is illustrated in the drawing in the manner previously described. 9 between the pistons 10 and 11 Will. be vented to atmosphere in the manner previously described, and the braking bars will therefore move, under the infiuence of gravity, to the positions in which the. main piston 10 engages the auxiliary piston 11 the projected position of the letter, which is the position in which the braking bars are illustrated in the drawing, and in which they will just clear freight car wheels of Ordinary width.

lVe will now assume that the operator wishes to move the bralting bars away from the rails far enough z.) permit a locomotive having the usual wide drivingA wheels to pass through the retarder without being` cngaged by the braking bars. To do this he Will'move lever L to its pl position, thereby opening contact 332, and closing contacts 311 and 321. The opening of contact 332 Will interrupt the circuit for valve V8 Which Was previously Furthermore,the region of cylinder closed at this contact, but the closing of contactV 321 Will complete another circuit for this Valve Wh ich is similar to the circuit Which Was previously closed at contact 332 With the excepticn that this latter circuit includes contact 321- instead lof contact 332. Valve V3 Will therefore remain energized. 1 The closing Vof contact 311 Will complete a circuit for valve 'V2 Which passes from battery B through line 'Wire 38, Winding` 19 of valve V2, line Wire 511, contact 311, and common Wire 41 back to battery B. Valve V2 Will therefore become energized, and Will connectl pipe With pipe 26. Valve V1 Will noW be deen-ergized and, as a result, When pipe 25 becomes connected With pipe 26, the region of cylinder 9 between the VauXiliary piston 11 and the distance piece 12 Will become connected With atmosphere through port 23, pipes 22 and 21, Valve V1, pipe 25, Valve-V2, pipe 26, Valve V3 and port 57. The force exerted by the bias of the braking bars and the levers 6 and 7 Will therefore cause pistons 10 and'11v and the cylinder 9 to move to the relative postions in Which thepiston 11 engages the distance piece 12, and the piston 10 engages the piston 11, thus permitting the braking` bars to move aWay from the rails the necessary amount to clear the Wide driving locomotive Wheels.

It isv Well known that some railroads employ locomotives having unusua-lly Wide driving Wheels, and When it is desired to use braking apparatus einbodying our invention e von these railroads, `the c istance piece 12 may he removed from cylinder 9 as shown in Fig. 2. The only dilferencethat this change Will make in the operation of the apparatus is that When' lev-er L is moved. to its` pl posi- -tion in the manner just described lthe pistons 10 and 11 and cylinder 9 instead of moving to the relative postions in Which the piston V11 engages the distance piece 12 and the piston 10 engages the piston 11, Will move to the relative positions in Which the piston 11 engages the upper end of the cylinder 9 and the piston 10 engages the piston 11, thus providing additional openingl of the braking bars, and h-ence permitting the braking -bars to clear the unusually Wide driving Wheels. One advantage of this arrangeme'nt is that the same parts maybe used for all railroads, thus reducing manufacturing costs. a v

- It should also be pointedv out that, since With apparatus embodying our invention, the

braking bars are normally permitted tov open only vto the positions in Which they Will clear freight car Wheels of usual Width,`the amount offluid pressure Which must be supplied to the motor to move the braking' bars to other braking positions durng the classification of cars is considerably less than the amount-Which Would have to 'be supplied to the motor if the braking bars Were normally permitted to open sufliciently to clear the Wide driving Wheels of locomotives.

Although We have herein shown` and described only one form of apparatus embodying our invention, it is understood that various changes and modii'ication's may be made therein Within the scope of the appcnded claims Without departing from the spirit and scope of our invention. v

Having thus described our invention, What We. claim is: L

1. Railway braking apparatus comprising two braking bars located on opposite sides ofV a track rail and biased to positions in Which lthey Will 'clear' the Wide driving Wheels of locomotives, poWer operated'means for moving said braking bars toWard the rail into positions in Which they Will engage the Wheels of a'car to retard the speed ofthe car, and means for at times arresting the movement ofsaid braking bars in response to their bias When the braking Vbars have reached thepositions in Which they Will just clear car Wheels of Ordinary Width. A

2. Railway braking apparatus comprising tWo -braking bars located on opposite sides of a track railV and biased to positions in Which they Will 'clear' the Wide driving Wheels of lo'comotives, poWer operated meanshfor moving` said braking bars toward the rail into positions ln' Which they Will engage the Wheels of a car to retard the speed of'the car, and means for normally arresting the movement of sald brakinfr bars in response to their-bias at the positions in Which thev Will iust clear Vcar Wheels of ordinarv Width lbut'for at othertimes permitting said brakmoving said braking bars to positions inV Which theywill engage the Wheels of a car to retard the speed of the car, and means for at times arresting the movement of said braking bars inresponse to their bias When. the braking'bars have reached Vthe positions in Which they Will just clear car Wheels of ordinary Width.`

4. 'Railway braking apparatus comprising tWo braking bars vlocated on opposite sides lof a track rail, tWo pivoted levers for supporting saidlbraking bars, a cylinder connected to one braking bar, a piston in said cylinderV operatively connected With the other braking bar, means for supply'ing fluid pressure to said cylinder `to operate said braking bar, and means for controlling the length of the stroke of said piston.

5. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail, two pivoted levers for supporting said braking bars, a cylinder connected to one braking bar, a piston in said cylinder operatively connected with the other braking bar, means for supplying fluid pressure to said cylinder to operate said braking bar, and means controlled from a remote point for at times varying the length of the stroke of said piston.

6. Railway braking appai'atus comprising two braking bars located on opposite sides of a track rail and movable toward and away from the rail into braking and non-braking positions, two levers for supporting said braking bars, said levers being pivotally supported for rotation about a common axis in such manner that said braking bars are biased by gravity to their non-braking positions, a cylinder connected with and supported by one of said levers, a piston in said cylinder operatively connected with the other lever in such manner that movement of said piston in one direction will move said braking bars to their braking positions, means for at times supplying said cylinder with fluid pressure in such inanner that said piston is moved in said one direction, and means in said cylinder for at times limiting the movement of said piston in the opposite direction to limit the movement of said braking bars away from said track rail.

7. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail and movable toward and away from the rail into braking and non-braking positions, two levers for' supporting said braking bars, said levers being pivotally supported for rotation about a common axis in such manner that said braking bars are biased bygravity to their non-braking positions, a cylinder connected with and supported by one of said levers, a piston in said cylinder operatively connected with the other lever in such manner that movement of said piston in one direction'will move said braking bars to their braking positions,.means for at times supplying said cylinder with fluid pressure in such manner that said piston is moved in said one direction, and fluid pressure operated means for at times limiting the movement of said piston in the opposite direction to limit the movement of said braking bars away from said track rail.

^ 8. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail and movable toward and away from the rail into braking and non-braking positions, two levers for supporting said braking bars, said levers being pivotally supported for rotation about a common axis in such manner that said braking bars are biased by gravity to their non-braking positions, a cylinder connected with and supported by one of said levers, a piston in said cylinder operatively connected with the other lever in such manner that movement of said piston.

to one braking bar, a first piston movable in said cylinder between'one end of the cylinder and an intermediate point, a second piston in said cylinder movable between the other end of the cylinder and said first piston and operatively connected with the other braking bar, and means for selectively supplyingfluid pressure to said cylinder between said first piston and the adjacent end of the cylinder and to the cylinder between said pistons.

10. Railway braking apparatus comprisng two braking bars located on opposite sides of a track rail, two pivoted levers for supporting said braking bars, a cylinder sccured to one braking bar, a removable distance piece in one end of said cylinder, a first piston inovable in said cylinder between said distance piece and an intermediate point, a second piston in said cylinder inovable between the other end of the cylinder and said first piston and operatively connected with the other braking bar, and means for selectively supplying fluid pressure to said cylinder between said first piston and said distance piece and to the cylinder between said 51' pistons.

11. Railway braking apparatus coinprising two `braking bars located on opposite sides of a track rail, two pvoted levers for supporting said braking bars, a cylinder secured to one braking bar, a first piston movable in said cylinder between one end of the cylinder and an intermediate point, a second piston in said cylinder movable between the other end of the cylinder and said first piston and operatively connected with the other braking bar, a first Valve for controlling the supply of fluid pressure to said cylinder between said auxiliary piston and the adj acent end of the cylinder, a second valve for conf'? trolling` the admission of fluid pressure to said cylinder between said pistons, and means for selectively controlling` said Valves.

12. Railway braking apparatus comprising two braking bars located on opposite sides of .by ,said first, third and 'fourth ya;

.porting said a track rail, two pvoted levers for supporting said braking bars, a cylinder secured to one braking` bar, a first piston movabie in said cylinder between one end of the cylinder and an intermediate point, a second piston in said cylinder inovable between the other end of the cylinder and said first piston and operatively connected with the other braking bar, a first Valve-for controlling the'supply of fiuid pressure to said cylinder between said auxiliary piston and the adjacent end of the cylinder, a second'valve for ccntrolling` the admission of fluid pressure to said cylinder between said pistons, a third Valve, means controlled by said second and third valves for controlling' the enhaust of fluid pressure from said cylinder between said pistons,'and means for selectively controlling said valves.

13. VRailway braking apparatus comprising two braking bars located on opposite sides of a track rail, two pvoted levers for supporting said braking bars, a cylinder secured to one braking bar, a firstzpisto'n movable in said cylinder between one end of the cylinder and an intermediate point, asecond piston in said cylinder movable between the other end of the cylinder and said first piston and operatively connected with the other braking` bar, a first Valve for controlling` the supply of fluid pressure to said cylinder betweensaid auXiliary piston and th-e adjacent end of the cylinder, a second Valve for controlling the admissicn of fluid pressure to said .cylinder between said pistons, a third Valve,-means controlled by said second and third valves for controlling the exhaust of fluidpressure from said cylinder between said pistons, a fourth Valve, Vmeans controlled vcs Vfor controllinfr the exhaust of fluid pressure from said cylinder between said auXiliary'piston and the adjacent end of the cylinder, and means for selectively conty alling said Valves.

14. Railway braking` apparatus comprising two braking bars locatedon opposite sdes of a traclrrail, twopiyoted ,brakinw bars, a cylinder secured to one braking bar,l a rem Vable distance piece in one'end of said cylinder, a first pis'- ton movable in said cylinder between said distance piece and an intermediate point, a second piston in saidcylinder inoyable between the other end of the cylinder and said first piston and operativeiy connected with the other bra'kinf;` bar, a first Valve cou-A trolling` the supply of fluid pressure to said cylinder between said auiliary priston and the adjacent end of the cylinder, second Valve for controlling the admission of fluid pressure to said cylinder betweensaid pistons, and means for selectively controlling said valves.

15. Railway braking apparatus -con'ipri sing; two brakmg bars located on opposite Sides of a track rail, two pvoted levers for suplevers for i supporting said braking` bars, a cylinder secured to one braking bar, a first piston movable in said cylinder between one end of the cylinder and an intermediate point, a second piston in said cylinder movable between the other end of the cylinder and said first pi ton and operatively. connected withJ brakthe otlle ing` bars, a first Valve for controlling` the admission of fluid to said cylinder between said auxiliary piston and the end of the cylinder, a second Valve, means controlled by said first and second valves for cont-rolling; the admission of fluid to said cylinder between said pistons, a third Valve, means controlled ling the exhaust of fluid from sL id cylinder between said pistons, a fourth Valve; means controlled by said first, third and fourth valves for controlling the exhaust of fluid for by said second and third valves for controll`.0

said lcylinder between said auxiliaryi piston ,395

cured to one bre-.king bar, a first piston movable in said cylinder between. one end of the cylinder and an intermediate point, a second piston in said cylinder movable between the other end of the cylinder and said first piston'and operatively connected with the other F braking bars, a first Valve for controlling the admission of fluid to said cylinder between said auxiliary piston and the adjacent end of the cylinder, a second Valve, means controlled by said first and second valves for controlling the admission of fluid to said cylinder vbetween said pistons, a third Valve7 means controllcd by said second and third Valves for controlling the ezhaust of fiuid from said cylinder between said pistons, a: fourth Valve meansl controlled by said first, third and fourth valves for controlling ythe exhaust of fluid from said cylinder between said auX- iliary piston and the adjacent end of the cylinder, a plurality of devices responsive to the pressure in said cylinder .between said pistons, a manually operable lever, means controlled by said lever for controllng` said first and'fourth valves, and means'controlled by said lever andfby said devices for control- 11.20

l ing said second and third valves. A

17. lRailway braking apjoaratus comprising' twobraking bars located on opposite sides of a track rail, two pvoted levers for sul porting said braking' bars, a cylinder secured `to one braking` bar, a first piston movable in said cylinder bemfeen one end of the cylinder and landintermediate point, a'second piston in said cylinder movable lbetween the other p end of the cylinder and said firstzpiston and operatively connected with the other braking bars, a first Valve for controlling the admission of fluid said cylinder between said auxiliary piston and the adjacent end of the cylinder, a second Valve, means controlled by said first and second valves for controlling the admission of fluid to said cylinder between said pistons, a third Valve, means controlled by said second and third valves for controlling the exhaust of fluid from said cylinder between said pistons, a fourth Valve; means controlled by said first, third and fourth valves for controlling the exhaust of fluid from said cylinder between said auxiliary piston and the adjacent end of the cylinder, means .responsive to the pressure in said cylinder between said pistons for controlling said second Valve; and means for controlling` said first, third and fourth valves.

18. Railway brakinff apparatus comprising two braking bars located on opposite sides of a track rail and movable toward and away from the rail into braking and non-braking,` positions, two levers for supporting said braking` bars, said levers being pivotally supported for rotation about a common axis in such manner that said braking bars are biased by gravity to their non-braking positions, a cylinder connected with and supported by one of said levers, a removable distance 1)iece in one end of said cylinder, an auxiliary piston movable between said distance piece and an intermediate point in the cylinder, a main piston in said cylinder movable between the other end of the cylinder and said auxiliary piston and operatively connected with the other braking bar in such manner that movement of said main piston toward said one end of the cylinder` will move said braking bars toward their braking positions, four magnet valves, means effective when a first one of said valves is energized for supplying fluid pressure to said cylinder between said auxiliary piston and said distance piece, means effective when a second one of said valves and said first Valve are both energized for supplying fluid pressure to said cylinder between said pistons, means elfective when a third one of said valves is energized and said second Valve is deenergized for connecting said cylinder betweensaid pistons with atmosphere, means effective when the remaining Valve is energized and 'said first and third valves are both deenergized for connecting said cylinder between said auxiliary piston and said distance piece with atmosphere, and means for selectively controlling` said valves.

19. Railway braking apparatus comprising two braling bars located on opposite sides of a track rail and movable toward and away from the rail into braking and non-braking positions, two levers for supporting said braking bars, said levers being pivotally supported for rotation about a common axis in such manner that said braking bars are biased by gravity to their non-braking positions, a cylinder connected with and supported by one of said levers, a distance piece in one end of said cylinder, an auxiliary piston movable between said distance piece and an intermediate point in the cylinder, a main piston in said cylinder movable between the other end of the cylinder and said distance piece and operatively connected with the other braking bar in such manner that movement of said main piston toward said one end of the cylinder will move said braking bars toward their braking positions, four magnet ValVes, means effective when a first one of said valves is energize'd for supplying fluid pressure to said cylinder between said auXiliary piston and said distance piece, means effective when a second one of said Valves and said first Valve are both energized for supplying fluid pressure to said cylinder between said piston, means ef- 'fective when a third one of said valves is energized and said second Valve is deenergized for connecting said cylinder between said pistons with atmosphere, means effective when the remaining Valve is energized and said first and third valves are both deenergized for connecting said cylinder between said auxiliary piston and said distance piece with atmosphere, a plurality of devices responsive to the pressure in said cylinder between said pistons, a manually operable lever, means controlled by said lever for selectively energizing said valves, and means controlled by said pressure responsive devices for controlling said second and third valves.

20. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail and capable of assuming positions in which they will clear the wide driving wheels of locomotives, power operated means for moving,` said braking bars toward the rail into positions in which they will engage the wheels of a car to retard the speed of the car, and means for at times arresting the movement of said braking bar away from the rail when the braking bars have reached the positions in which they will just clear car wheels of Ordinary width.

In testimony whereof we affix our signatures.

HAROLD O. CLAUSEN. JOHN W. LOGAN, JR. 

